20859972 has 48 divisors (see below), whose sum is σ = 56189952. Its totient is φ = 5899680.

The previous prime is 20859953. The next prime is 20859977. The reversal of 20859972 is 27995802.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (20859977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7447 + ... + 9857.

It is an arithmetic number, because the mean of its divisors is an integer number (1170624).

Almost surely, 2^20859972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20859972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28094976).

20859972 is an abundant number, since it is smaller than the sum of its proper divisors (35329980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20859972 is a wasteful number, since it uses less digits than its factorization.

20859972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2528 (or 2526 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 20859972 is about 4567.2718333815. The cubic root of 20859972 is about 275.2778327095.

The spelling of 20859972 in words is "twenty million, eight hundred fifty-nine thousand, nine hundred seventy-two".